Brake pedal interfacing with hydrostatic drive

Patent metadata

Field	Value
Publication number	US-10112586-B2
Application number	US-201615140782-A
Country	US
Kind code	B2
Filing date	Apr 28, 2016
Priority date	Apr 29, 2015
Publication date	Oct 30, 2018
Grant date	Oct 30, 2018

Abstract

An improved system for braking an agricultural vehicle propelled by a hydrostatic drive unit is disclosed. An operator provides a desired speed command from a first user interface, such as a joystick. The joystick generates a command responsive to the deflection and communicates the command to a controller. The agricultural vehicle also includes a second user interface, such as a brake pedal. The brake pedal includes a transducer configured to generate a signal corresponding to a deflection of the brake pedal which is also communicated to the controller. If the operator presses the brake pedal when the joystick is commanding motion, the controller reduces the signal from the joystick. The amount the signal is reduced increases as the deflection of the brake pedal increases until the brake pedal overrides any speed command from the joystick.

First claim

We claim:

1. A system for stopping an agricultural vehicle, comprising;
a first user interface operable to provide a first command signal corresponding to a desired travelling speed of the agricultural vehicle;
a second user interface operable to generate a second command signal corresponding to a desired braking of the agricultural vehicle; and
a controller configured to receive each of the first and the second command signals and to generate a third command signal to a hydrostatic drive unit for the agricultural vehicle as a function of the first and second command signals;

wherein:
the controller generates an interlock disabling the hydrostatic rive unit when the first command signal indicates the first user interface is not a neutral position and the second command signal exceeds a predefined threshold; and
the controller releases the interlock when the first command signal indicates the first user interface is at the neutral position.

2. The system of claim 1 wherein the first user interface is a joystick and wherein the first command signal has a range between zero speed and full speed corresponding to a range of deflection of the joystick.

3. The system of claim 2 wherein the second user interface is a brake pedal having a transducer, wherein the transducer generates the second command signal corresponding to a range of deflection of the brake pedal.

4. The system of claim 3 wherein the third command signal to the hydrostatic drive unit corresponds to the first command signal when the brake pedal is at a neutral position and the third command signal to the hydrostatic drive unit is reduced from the first command signal by the second command signal as the brake pedal travels through the range of deflection of the brake pedal.

5. A system for stopping an agricultural vehicle, comprising;
a first interface operable to provide a first command signal corresponding to a desired travelling speed of the agricultural vehicle;
a second user interface operable to generate a second command signal corresponding to a desired braking of the agricultural vehicle; and
a controller configured to receive each of the first and the second command signals and to generate a third command signal to a hydrostatic drive unit for the agricultural vehicle as a function of the first and second command signal;

wherein:
the first user interface is a joystick and wherein the first command signal has a range between zero speed and full speed corresponding to a range of deflection of the joystick;
the second interface is a brake pedal having a transducer, wherein the transducer generates the second command signal corresponding to a range of deflection of the brake pedal; and
the controller generates an interlock disabling the hydrostatic drive unit when the first command signal indicates the joystick is not at a neutral position and the second command signal exceeds a predefined threshold and wherein the controller releases the interlock when the first command signal indicates the joystick is at the neutral position.

6. The system of claim 3 wherein the system further comprises a set of service brakes and wherein the range of deflection of the brake pedal generates a fourth command signal to control operation of the service brakes to slow the agricultural vehicle.

7. A system for stopping an agricultural vehicle, comprising:
a joystick operable to provide a first command signal corresponding to a desired travelling speed of the agricultural vehicle;
a brake pedal, including a transducer operable to generate a second command signal corresponding to a range of deflection of the brake pedal; and
a controller configured to receive each of the first and the second command signals and to generate a third command signal to a hydrostatic drive unit for the agricultural vehicle as a function of the first and second command signals

wherein:
the controller generates am interlock disabling the hydrostatic drive unit when the first command signal indicates the joystick is not at a neutral position and the second command signal exceeds a predefined threshold; and
the controller releases the interlock when the first command signal indicates the joystick is at the neutral position.

8. The system of claim 7 wherein the first command signal has a range between zero speed and full speed corresponding to a range of deflection of the joystick and wherein the third command signal corresponds to the first command signal when the brake pedal is in a neutral position.

9. The system of claim 8 , wherein the third command signal is reduced by the second command signal corresponding to the range of deflection of the brake pedal.

10. A system for stopping an agricultural vehicle, comprising;
a joystick operable to provide a first command signal corresponding to a desired travel speed of the agricultural vehicle;
a brake pedal, including a transducer operable to generate a second command signal corresponding to a range of deflection of the brake pedal:, and
a controller configured to receive each of the first and the second command signals and to generate a third command signal to a hydrostatic drive unit for the agricultural vehicle as a function of the first and second command signals;

wherein:
the first command signal has a range between zero speed and full speed corresponding to a range of the joystick;
the third command signal corresponds to the first command signal when the brake pedal is in a neutral position;
the joystick includes a neutral position; and
the controller sets an interlock on motion of the agricultural vehicle when the deflection of the brake pedal exceeds a predefined threshold and the joystick is not in the neutral position and the controller resets the interlock when the joystick returns to the neutral position.

11. The system of claim 10 wherein the system further comprises a set of service brakes and wherein the range of deflection of the brake pedal generates a fourth command signal to control operation of the set of service brakes to slow the agricultural vehicle.

12. The system of claim 11 wherein:
the range of deflection of the brake pedal includes a first segment, a second segment, and a third segment;
during the first segment, the third command signal is reduced to a predefined, non-zero level without generating the fourth command signal;
during the second segment, the third command signal is reduced to zero and the fourth command signal is generated to a level less than a full braking force; and
during the third segment, the fourth command signal is increased to the full braking force.

13. A method for controlling a speed of travel of an agricultural vehicle, comprising the steps of:
generating a first command signal with a first user interface, wherein the first command signal corresponds to a desired speed of travel of the agricultural vehicle;
generating a second command signal with a second user interface, wherein the second command signal corresponds to a desired braking of the agricultural vehicle;
receiving the first command signal and the second command signal at a controller on the agricultural vehicle;
generating a third command signal with the controller responsive to both the first command signal and the second command signal; and
transmitting the third command signal to a hydrostatic drive unit for the agricultural vehicle, Wherein the hydrostatic drive unit supplies hydraulic fluid to a plurality of hydraulic motors on the agricultural vehicle responsive to the third command signal, the plurality of hydraulic motors controlling the speed of travel of the agricultural vehicle;

where

Assignees

• Cnh Ind America Llc

Inventors

• Brooks Nathan Paul
• Treinen Kerry J

Classifications

• B60K17/10

  of fluid gearing · CPC title

• B60K2026/029

  Joystick type control devices for acceleration · CPC title

• B60Y2200/22

  Agricultural vehicles · CPC title

• B60T7/042 Primary

  by electrical means, e.g. using travel or force sensors · CPC title

• B60K7/0015

  the motor being hydraulic · CPC title